2018-19 Solar Car Challenge Blog

Suspending Belief with our Suspension

It can hardly be argued that some of the most important parts of a car are the wheels, it wouldn’t be much of a car without them. However, in order to comply with the rules of the Solar Car Competition (and protect the rear of the poor soul who has to drive the car), we can’t simply bolt some wheels to the chassis, we need a suspension system.

Very Early and rough Concept Work

As with all good things, we began with basic concept work and brainstorming. Because of the unusual profile of our car’s chassis, we had a number of options for the type of suspension we would use, be it a vertically mounted hinge, a side mounted off-road style shock, or a large lever arm in the style of a motorcycle rear wheel.

2d Geometry Layout of Front Wheel

2d Geometry Layout of Rear Wheels

Through this process we came to the decision to use a very simple vertical hinge system. This was intended to be the most modular option which would also provide us the most adjustment potential and the most control over the behavior of the geometry. On this note, the next step before moving to 3d-designing was planning out the behavior and geometry of our suspension in 2d. These drawings, though not the prettiest would provide a critical framework for later 3d models and would clarify the necessary part dimensions in order to achieve suspension with a 3in travel distance and shocks that remain largely straight across the travel distance.

Early 3d Model

Once this baseline had been established, we moved to preliminary 3d model work. This was still rough, but would seek to provide us with an idea of how the suspension would fit in 3d space and give us an idea of the weight, complexity of manufacturing, and the metal stock, fasteners, and shocks that would be required. Furthermore, having a 3d model would allow us to explore mounting options.

Following this preliminary draft, we moved on to completing a final draft which will be used to build the actual suspension. This final stage began around the time of our Shift from Invetor to Solidworks, and so this would become one of the first major subsystems to be designed using this new and powerful software.

Rear Suspension Production Model

Front Suspension Production Model

The two above designs reflect a combination of the second two phases of the design process, incorporating the geometry of the second phase, while maintaining the manufacturing practicality and realistic grounding of the preliminary 3d draft.

As of now, we are currently in pre-production phases for the final design, as necessary parts are variously cataloged, bought, or fabricated. We are also in the process of finalizing attachment methods between the chassis and assembly. We hope to have the suspension systems mounted to the chassis in early January.